I count: 39 lands and Pantlaza, Sun-Favored, Ixalli's Lorekeeper, Drover of the Mighty, Marauding Raptor, Otepec Huntmaster, Atzocan Seer, Ranging Raptors, Topiary Stomper, Wayward Swordtooth, Farseek, Rampant Growth, Thunderherd Migration, Cultivate, Migration Path, Sol Ring, Arcane Signet, Progenitor's Icon, Regal Behemoth 57 mana
Cards like Sunforger, Heartseeker, and Argentum Armor suddenly become even more playable
Add to that some actually pretty interesting lore, I think Bloomburrow has a lot to give for those who are interested in the storytelling aspects of Magic too, giving the set a wide potential audience
Rather than creating a set full of cards that complement each other to make for a truly unique and interesting draft experience, it's simply everything
And there is a similar concept in Chains of Mephistopheles